Board of Governors of the Federal Reserve System (U.S.), 1935-. "Industry Groupings, Not Seasonally Adjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "January 14, 1969," G.12.3 Industrial Production (1969-01-14) : 5-5. https://fraser.stlouisfed.org/title/55/item/59546/toc/465852 , accessed on April 19, 2024.